1. Field of Invention
This invention relates to optical micromachined or microelectromechanical system based multiplexers and multiplexing methods.
2. Description of Related Art
Multiplexers are generally well-known. For example, an optical multiplexer/demultiplexer comprising an array of optical waveguides is described in U.S. Pat. No. 5,002,350 to Dragone. For optical applications, an optical add/drop multiplexer receives an input optical signal with many optical channels at different wavelengths from a single optical fiber. The optical signal is demultiplexed into separate optical channels based on their wavelengths. Once demultiplexed, each of the separate optical channels can either pass through the optical add/drop multiplexer to a multiplexer or be dropped. For any channel that is dropped, a new signal can be added to utilize that channel. The passed and added channels are remultiplexed into an output optical signal sent out on a single optical fiber.
Current optical add/drop multiplexers are assembled from discrete components including demultiplexers, switches and multiplexers. Typical multiplexers and demultiplexers include diffraction gratings in free space optics and arrayed waveguide gratings for guided wave optics. Optical switches are used for dropping, adding and passing channels.